A vivid biography of a 15th century patron of exploration, geographical observation, the Portuguese, Den Henrique, who spread the extent of men's knowledge of the physical world, and who opened the way for Vasco da Gama, and the inauguration of a new era. It is the story, too, of Portugal as a mighty nation, crusading against the Moors, carrying the Cross to all. It shows how Don Henrique's fleet charted new lands, provided a more exact maritime science, brought home weapons to fight mediseval ignorance. It indicates the importance of his work on the isolated promontory of Sagres where naval arsenal gave way to observatory and school for geography and navigation. While this might have been only a footnote to the history of the times, the author's flair for embellishing chronological and personal history with color and excitement makes this decidedly readable (which is certainly more than we expected).